Cannabinoids, such as Δ9-Tetrahydrocannabinol (a psychotropic) and cannabidiol (nonpsychotropic), i.e., ingredients found in cannabis, have shown anti-inflammatory and immunosuppressive properties in mouse models of GvHD and clinical trials, primarily through CB1, CB2, and non-cannabinoid receptors [13,14]. The gene discussed is CNR1; the disease is graft versus host disease.